As disclosed in William Rhodea, JACS, 83, 3690 (1961), it is known that heterocyclic rings forming DNA bases strongly absorb ultraviolet light (vicinity of 260 mm), and a hypochromic effect occurs wherein, due to the overlapping of the heterocyclic rings of the bases inside the double helix (stack structure), the optical absorption decreases. However, it is difficult to synthesize these types of polymer materials, and it is also difficult to control their optical properties. For example, as disclosed in Japanese Patent No. 2659245, a polymer wherein the side-chain is a functional group comprising an aromatic ring may be obtained by polymerizing a methacrylic acid ester having a triphenylmethyl group as the ester group. However, in this case, the aromatic rings in the functional group of the side-chain are not parallel and it is difficult to obtain a structure wherein they sufficiently overlap, so it was difficult to manifest optical properties.
As described in Yokoyama, M. Macromolecules, 8 (1975), 101 and Itaya, A, Chem. Phys. Lett. 138 (1987), 231, poly(N-vinylcarbazole) is a polymer wherein the side-chain is a functional group comprising an aromatic ring, and when it is present as a film, it is known to emit a blue light due to a carbazole excimer. However, as the functional group in the side-chain of this polymer cannot assume a stable stack structure, efficient excimer light emission does not occur.
As described in Nakano, Preliminary reports of the 48th Annual Meeting of the Society of Polymer Science, Japan (Polymer Preprints, Japan, 48(7), 1279(1999)), it is known that dibenzofulvene polymerizes, but as the polymer obtained has poor solubility and miscibility with other polymers, its detailed optical properties were not known.
The inventor therefore studied the optical properties of polymers comprising dibenzofulvene. As a result, he discovered that polymers obtained using dibenzofulvene having a substituent group had improved solubility; certain of these polymer compounds having a group containing certain aromatic rings in the side-chain had specific optical properties suggesting application as an ultraviolet transmitting material, electroluminescent material or laser material; and compositions wherein an electron acceptor compound or electron donor compound was added to these polymer compounds could be used as charge transfer materials. He thereby arrived at the present invention.
It is therefore a first object of the present invention to provide a polymer compound having a stable stack structure, showing a large hypochromic effect and which can be used as a light-resistant polymer material or ultraviolet transmitting material.
It is a second object of the invention to provide a composition containing a polymer compound having specific optical properties exhibiting highly efficient excimer light emission, emitting light from the ultraviolet region into the blue region, and which has application as an electroluminescent material or laser-emitting material.
It is a third object of the invention to provide a charge transfer material having a high charge mobility.
It is a fourth object of the invention to provide a polymerizing monomer to be used as a starting material for the aforesaid polymer compound.